cakephp / phinx

    {

        $instructions = new AlterInstructions();

        foreach ($columns as $column) {

            $rows = $this->fetchAll(sprintf(

                "SELECT

                tc.constraint_name,

                tc.table_name, kcu.column_name,

                ccu.table_name AS referenced_table_name,

                ccu.column_name AS referenced_column_name

            FROM

                information_schema.table_constraints AS tc

                JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name

                JOIN information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name

            WHERE constraint_type = 'FOREIGN KEY' AND tc.table_name = '%s' and ccu.column_name='%s'

            ORDER BY kcu.ordinal_position",

                $tableName,

                $column

            ));

            foreach ($rows as $row) {

                $instructions->merge(

                    $this->getDropForeignKeyInstructions($tableName, $row['constraint_name'])

                );

            }

        }

        return $instructions;

    }

    {

        $instructions = new AlterInstructions();

        foreach ($columns as $column) {

            $rows = $this->fetchAll(sprintf(

                "SELECT

                    CONSTRAINT_NAME

                  FROM information_schema.KEY_COLUMN_USAGE

                  WHERE REFERENCED_TABLE_SCHEMA = DATABASE()

                    AND REFERENCED_TABLE_NAME IS NOT NULL

                    AND TABLE_NAME = '%s'

                    AND COLUMN_NAME = '%s'

                  ORDER BY POSITION_IN_UNIQUE_CONSTRAINT",

                $tableName,

                $column

            ));

            foreach ($rows as $row) {

                $instructions->merge($this->getDropForeignKeyInstructions($tableName, $row['CONSTRAINT_NAME']));

            }

        }

        if (empty($instructions->getAlterParts())) {

            throw new \InvalidArgumentException(sprintf(

            return;

        } else {

            foreach ($columns as $column) {

                $rows = $this->fetchAll(sprintf(

                    "SELECT a.CONSTRAINT_NAME, a.TABLE_NAME, b.COLUMN_NAME, 

                    (SELECT c.TABLE_NAME from ALL_CONS_COLUMNS c 

                    WHERE c.CONSTRAINT_NAME = a.R_CONSTRAINT_NAME) referenced_table_name,

                    (SELECT c.COLUMN_NAME from ALL_CONS_COLUMNS c 

                    WHERE c.CONSTRAINT_NAME = a.R_CONSTRAINT_NAME) referenced_column_name

                    FROM all_constraints a JOIN ALL_CONS_COLUMNS b ON a.CONSTRAINT_NAME = b.CONSTRAINT_NAME

                    WHERE a.table_name = '%s'

                    AND CONSTRAINT_TYPE = 'R'

                    AND COLUMN_NAME = '%s'",

                    $tableName,

                    $column

                ));

                foreach ($rows as $row) {

                    $this->dropForeignKey($tableName, $columns, $row['CONSTRAINT_NAME']);

                }

            }

        }

    }